Fuel Mixture Oil to Gas Ratio Help!!!!!

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I do not believe there is a correct "ratio". It is relative to where you live. I am running 30/1,bike runs smooth and quiet in the morning when it is cool and damp. But on the way home when it is 85 degrees out it is extremely noisy. That is the nature of the cheap "china girl". Been riding mine for two years on the south shore of lake Erie
,summer and winter with no problems. So over all a fun experience,eats up brake pads and tires though.
 
I do not believe there is a correct "ratio". It is relative to where you live. I am running 30/1,bike runs smooth and quiet in the morning when it is cool and damp. But on the way home when it is 85 degrees out it is extremely noisy. That is the nature of the cheap "china girl". Been riding mine for two years on the south shore of lake Erie
,summer and winter with no problems. So over all a fun experience,eats up brake pads and tires though.


My tires and brake pads wear out quickly about every 150 to 200 miles. My first build is a 27.5 and hard to find street tries for it.
 
Dead boy what you described is a air/fuel mixture problem not a oil/fuel mixture problem. A 30/1 mixture ratio is good for lubrication, it sounds like your jetting is too lean. I like to jet mine so its a little rich when cold, then when its hot it runs like it should.
 
This is a GREAT read on the subject of premix ratios.

Fly

Ok, I now am a participant in the motorized bike world. Builder I bought the bike from ran 2-3 tanks through the bike and told me to run 20/1. I did and when the bike sits I have to put a paper plate under the pipe to catch all the blowby. The last time I rode it there was at least a teaspoon if not more of ooze that poured out while sitting overnight. I used to race Open Class two strokes in the So. Cal desert, District 37, Hare and Hounds. The last bike I raced was a KTM 540 DXC, an absolute beast of a bike. What I don't understand from the threads here is why I/we (and friends) always ran 50/1 with absolutely no problem whatsoever. Anything less was too much oil. And these threads talk about loosing hp with less oil and not running the bike to hard? WHAT ARE YOU GUYS SMOKING? And what is this garbage about the smaller the engine the higher the rpms? Did I read that right? What malarky.
 
Ok, I now am a participant in the motorized bike world. Builder I bought the bike from ran 2-3 tanks through the bike and told me to run 20/1. I did and when the bike sits I have to put a paper plate under the pipe to catch all the blowby. The last time I rode it there was at least a teaspoon if not more of ooze that poured out while sitting overnight. I used to race Open Class two strokes in the So. Cal desert, District 37, Hare and Hounds. The last bike I raced was a KTM 540 DXC, an absolute beast of a bike. What I don't understand from the threads here is why I/we (and friends) always ran 50/1 with absolutely no problem whatsoever. Anything less was too much oil. And these threads talk about loosing hp with less oil and not running the bike to hard? WHAT ARE YOU GUYS SMOKING? And what is this garbage about the smaller the engine the higher the rpms? Did I read that right? What malarky.
What we are running are not as well made as a KTM, Yamaha, Kawasaki etc, our clearances are much wider and the quality control at some of the manufacturing plants is non exsistant. If you have a well balanced and machined engine you can run a leaner fuel/oil ratio, I have as well owned many 2 stroke dirt bikes and ran a lot leaner ratios, but the wear that some of these engines show indicates more oil is needed. I have found that 32/1 with a synthetic smokeless oil works best for me.
 
I just take a standard 16 oz water bottle and fill the bottom 1/20 section with oil, and then shake and pour as needed. Simple, and effective for mixing and storage.
 
when i first bought my grubee gt5 i ran it at 16:1 like the manual said and thought that is way to lean and too much oil it will carbon up in a second. sure enough lol using the suplied oil and the recomended mix of 16:1 after i rode about 150 miles i took the motor apart for inspection ............ lolol lol lol 16:1 my but ! the whole top of the piston had a thick (for 150miles) layer of carbon and the cumbustion chamber on the head was crudded up and the cheap 3 prong spark plug was black as a cat and fould !!!! i knew i could get way more power from this thing if i modded it my own way.

i have no money but i have lots of tools so time for the...
FREE MODS !

so i took the cilynder and heaad off and gave the cilynder a good heavy port and polish, raised the exhaust about 3/16 and lowered the intake about 3/16 and widend bolth by 1/16 each side then decked it down a little with sandpaper and glass... then the piston i rounded the edges of it and made ramps for all the ports even the transfer ports effectively changing the timing ( if you look at the top of the piston now it has a 4 leaf clover pattern ground in it) and i cut a full 5/16 off the entire intake side of the piston skirt ! man its way lighter than before WAY lighter ! allowing for quicker rev's. along with the port time changes i made with the dremel i estimated it would be a lot better for mid to high rpm power.

the head i had to take a lot off because i ground a lot off the piston witch lowered the compression so i took .100 off the head and dremeled a new squish band in by hand then polished the chamber to a mirror finninsh and put in a nkg b5hs plug and made shure it did not hit the piston and it was in line with the intake port.

i also port matched the exhaust and intake by the way i am using the long intake ... the z one with a 2.5 in extention hose for addeed tourqe .

i installed a new set of rings after a slight honing of the cilynder (slight i said as i was scared the cheap chrome would flake just enough to put some honing marke back on there at 45s or so) and reasembled the motor. it has a lot of compression now way more than stock ! it tested at an average of 138psi !!!

i cut off the cheap crappy plug boot and just crimped a simple loop conector strait onto the plug wire and screw it onto the tip of the plug directly ( mutch better conection )

and since then i have been running my oil gas mix at 40:1 full synthetic ... i use promix at lowes or true fuel 40:1 premix

good god man after those FREE MODSmy motor feels like a whole new beast !!!! it is literaly 3 times more powerfull !!!! i can cruse comfortably at 30mph !!!!

after about 100 miles i tore down the top end to inspect its condition and wow is all i have to say ! running 40:1 full sythetic and 93 oct the combustion chamber looked spotless like a mirror still and the cilyender was spotless no signs of scratches or wear the piston was perfectly clean aside from the small brown spot where the spark plug was fireing and the plug looked like chocolate color but slightly darker than usual (probably because i was riding low rpms and going slow for a lil bit before shutting it off and tear down) the plug on normal inspection ... WOT then cut off looks perfect !!!

so my theroy is that these motor can run at 16:1 or 20:1 or 25:1 with regular oil but you will carbon the heck out of it and foul plugs like a mad man. also you wil never get the full potential out of the motor with so little gas in the mix and natural oil.
even in a bone stock motor i would recomend you run 32:1 to 40:1 and use full synthetic right out the box! even for break in that is how i broke in my new rings at 40:1 full synthetic and my engine has rediculous amounts of power compared to when it was stock and at 16:1.

so i tell everyone who ask me what i run ... 40:1 full synthetic 93 oct. i recomend that mix also to all who have a grubee gt5 if your stock compresion then use 87oct 40:1 if your high comp the 93oct 40:1
some higher grade better more well designed oils for motor crross race bike can be run at 50:1 to 75:1 but i personaly would never go over 50:1 on this type of engine as it does need significant lubrication ! the parts are cheaply made and tolerances are not to spec so pushing the limit of how little oil you can use... it is very stupid for sutch a tiny insignificant gain if there even is any .... i would rather run 40:1 full syn and know i am safley lubed and getting the proper amount of air fuel mix than run 16:1 and be lean and foul up my engine or 75:1 and be to rich and stressing all my bearings and every moving part with unnessasary heat and preasure

i also tried running it at 50:1 full syn with lucas oil upper cilynder lube added to the gas and the differance was neglegable i hardly noticed a thing and my plug looked like it was getting lighter in color and straying off from the good coco color i want so i swapped back to 40:1 and add a little (1oz) of lucas oil upper cilyender lube every other tank.


Some years have passed, and they still recommend the crazy 16:1 ratio... I readed your whole post, thanks, you really helped me.
 
I have only used Valvoline Multi-Purpose 2 cycle oil mixed 32:1 in all my 2 strokes for over 10 years with no problems. I find the oil at Auto Zone
 
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